'''Wayland''' is a new windowing protocol for Linux. Utilization of Wayland requires changes to and re-installation of parts of your system's software. For more information on Wayland see its [http://wayland.freedesktop.org/ homepage].

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[http://wayland.freedesktop.org/ Wayland] is a protocol for a [[wikipedia:Compositing window manager|compositor]] to talk to its clients, as well as a library implementing this protocol. Many major Linux desktop environments, like Gnome and KDE, support Wayland. There is also a compositor reference implementation called "Weston". [https://wayland.freedesktop.org/xserver.html XWayland] implements a compatibility layer to seamlessly run legacy X11 applications on Wayland.

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{{Warning|Wayland is under heavy development. Support can not be guaranteed and it may not function as you expect.}}

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== Requirements ==

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== Requirements ==

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Most Wayland compositors only work on systems using [[KMS]].

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Currently Wayland will only work with on a system that is utilizing [[KMS]].

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Wayland by itself does not provide a graphical environment; for this you also need a compositor such as [[#Weston]] or [[Sway]], or a desktop environment that includes a compositor such as [[GNOME]] or [[KDE]].

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=== Buffer API support ===

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== Installation ==

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For the GPU driver and Wayland compositor to be compatible they must support the same buffer API. There are two main APIs: [[Wikipedia:Generic Buffer Management|GBM]] and [http://www.phoronix.com/scan.php?page=news_item&px=XDC2016-Device-Memory-API EGLStreams].

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You need to build and install {{AUR|wayland-git}} and {{AUR|mesa-full-wayland}} from the [[AUR]]. Replacement of the Mesa stack is required because the stock one does not support Wayland.

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== Usage ==

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{| class="wikitable"

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As Wayland is only a library, it is useless on its own. To use it, you need a compositor (like Weston), Weston demo applications, Qt5 (or Qt4 with QPA enabled) with Wayland plugin, and/or GTK+ with Wayland support.

{{ic|card0}} is the unused built-in video adapter. The add-on adapter {{ic|card1}} is cabled to one HDMI and one DVI monitor, so the output names are {{ic|HDMI-A-1}} and {{ic|DVI-I-1}}.

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{{hc|~/.config/weston.ini|<nowiki>

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[core]

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# xwayland support

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xwayland=true

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[libinput]

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enable_tap=true

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[shell]

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background-image=/usr/share/backgrounds/gnome/Aqua.jpg

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background-color=0xff002244

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panel-color=0x90ff0000

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locking=true

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animation=zoom

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close-animation=fade

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focus-animation=dim-layer

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#binding-modifier=ctrl

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#num-workspaces=6

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### for cursor themes install xcursor-themes pkg from Extra. ###

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#cursor-theme=whiteglass

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#cursor-size=24

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### tablet options ###

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#lockscreen-icon=/usr/share/icons/gnome/256x256/actions/lock.png

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#lockscreen=/usr/share/backgrounds/gnome/Garden.jpg

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#homescreen=/usr/share/backgrounds/gnome/Blinds.jpg

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#animation=fade

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### for Laptop displays ###

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#[output]

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#name=LVDS1

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#mode=1680x1050

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#transform=90

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#[output]

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#name=VGA1

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# The following sets the mode with a modeline, you can get modelines for your preffered resolutions using the cvt utility

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#mode=173.00 1920 2048 2248 2576 1080 1083 1088 1120 -hsync +vsync

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#transform=flipped

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#[output]

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#name=X1

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#mode=1024x768

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#transform=flipped-270

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[input-method]

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#path=/usr/lib/weston/weston-keyboard

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[keyboard]

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keymap_rules=evdev

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#keymap_layout=gb,de

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#keymap_options=caps:ctrl_modifier,shift:both_capslock_cancel

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### keymap_options from /usr/share/X11/xkb/rules/base.lst ###

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numlock-on=true

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[terminal]

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#font=DroidSansMono

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#font-size=14

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[launcher]

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icon=/usr/share/icons/gnome/24x24/apps/utilities-terminal.png

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path=/usr/bin/weston-terminal

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[launcher]

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icon=/usr/share/icons/gnome/24x24/apps/utilities-terminal.png

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path=/usr/bin/gnome-terminal

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[launcher]

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icon=/usr/share/icons/hicolor/24x24/apps/firefox.png

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path=/usr/bin/firefox

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[launcher]

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icon=/usr/share/weston/icon_flower.png

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path=/usr/bin/weston-flower

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[screensaver]

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# Uncomment path to disable screensaver

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path=/usr/libexec/weston-screensaver

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duration=600

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</nowiki>

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}}

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Minimal {{ic|weston.ini}} :

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{{hc|~/.config/weston.ini|<nowiki>

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[core]

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xwayland=true

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[keyboard]

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keymap_layout=gb

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[output]

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name=LVDS1

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mode=1680x1050

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transform=90

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[launcher]

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icon=/usr/share/icons/gnome/24x24/apps/utilities-terminal.png

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path=/usr/bin/weston-terminal

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[launcher]

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icon=/usr/share/icons/hicolor/24x24/apps/firefox.png

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path=/usr/bin/firefox

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</nowiki>

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}}

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==== XWayland ====

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[[Install]] the {{Pkg|xorg-server-xwayland}} package.

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When you want to run an X application from within Weston, it spins up Xwayland to service the request. The following configuration is shown above:

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{{hc|~/.config/weston.ini|

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<nowiki>[core]

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modules=xwayland.so</nowiki>

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}}

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{{Note| if X is not already configured you may need to configure a keymap: [[Keyboard configuration in Xorg]]}}

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==== Screencast recording ====

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Weston has build-in screencast recording which can be started and stopped by pressing the {{ic|Super+r}} key combination. Screencasts are saved to the file {{ic|capture.wcap}} in the current working directory of Weston.

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The WCAP format is a lossless video format specific to Weston, which only records the difference in frames. To be able to play the recorded screencast, the WCAP file will need to be converted to a format which a media player can understand. First, convert the capture to the YUV pixel format:

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$ wcap-decode capture.wcap --yuv4mpeg2 > capture.y4m

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The YUV file can then be transcoded to other formats using [[FFmpeg]].

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==== High DPI displays ====

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For [[wikipedia:Retina_Display|Retina]] or [[HiDPI]] displays, use:

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{{hc|~/.config/weston.ini|

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<nowiki>[output]

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name=...

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scale=2</nowiki>

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}}

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==== Shell font ====

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Weston uses the default sans-serif font for window title bars, clocks, etc. See [[Font configuration#Replace or set default fonts]] for instructions on how to change this font.

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== GUI libraries ==

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See details on the [http://wayland.freedesktop.org/toolkits.html official website].

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=== GTK+ 3 ===

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The {{Pkg|gtk3}} package has the Wayland backend enabled. GTK+ will default to the Wayland backend, but it is possible to override it to Xwayland by modifying an environment variable: {{ic|GDK_BACKEND&#61;x11}}.

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=== Qt 5 ===

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To enable Wayland support in Qt 5, install the {{Pkg|qt5-wayland}} package.

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To run a Qt 5 app with the Wayland plugin, use {{ic|1=-platform wayland}} or set the {{ic|1=QT_QPA_PLATFORM=wayland-egl}} [[environment variable]].

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=== Clutter ===

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The Clutter toolkit has a Wayland backend that allows it to run as a Wayland client. The backend is enabled in the {{Pkg|clutter}} package.

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To run a Clutter app on Wayland, set {{ic|CLUTTER_BACKEND&#61;wayland}}.

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=== SDL2 ===

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To run a SDL2 application on Wayland, set {{ic|SDL_VIDEODRIVER&#61;wayland}}.

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=== GLFW ===

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To use GLFW with the Wayland backend, install the {{Pkg|glfw-wayland}} package (instead of {{Pkg|glfw-x11}}).

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=== GLEW ===

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To use GLEW with the Wayland backend, install the {{Pkg|glew-wayland}} package (instead of {{Pkg|glew}}).

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=== EFL ===

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EFL has complete Wayland support.

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To run a EFL application on Wayland, see Wayland [http://wayland.freedesktop.org/efl.html project page].

| [[Velox]] is a simple window manager based on swc. It is inspired by [[dwm]] and [[xmonad]].

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|-

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| Orbital

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| Stacking

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| [https://github.com/giucam/orbital Orbital] is a Wayland compositor and shell, using Qt5 and Weston. The goal of the project is to build a simple yet flexible and good looking Wayland desktop. It is not a full fledged DE but rather the analogue of a WM in the X11 world, such as [[Awesome]] or [[Fluxbox]].

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|-

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| Liri Shell

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| Stacking

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| [https://github.com/lirios/shell Liri Shell] is the desktop shell for [[Liri]], built using QtQuick and QtCompositor as a compositor for Wayland.

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|-

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| Maynard

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| ''(Unclear)''

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| [https://github.com/raspberrypi/maynard Maynard] is a desktop shell client for Weston based on GTK. It was based on weston-gtk-shell, a project by Tiago Vignatti.

Some of installed wayland desktop clients might store information in {{ic|/usr/share/wayland-sessions/*.desktop}} files about how to start them in wayland.

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==Troubleshooting==

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$ weston-image image1.jpg image2.jpg...

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Displays images.

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$ weston-view doc1.pdf doc2.pdf...

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=== Running graphical applications as root ===

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Displays PDF files.

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== Qt ==

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Trying to run a graphical application as root via [[su]], [[sudo]] or [[polkit|pkexec]] in a Wayland session (''e.g.'' [[GParted]] or [[Gedit]]), be it in a terminal emulator or from a graphical component, will fail with an error similar to this:

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=== Installation ===

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{{bc|$ sudo gedit

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You need to build and install {{AUR|qt-qpa}} from [[AUR]]. It contains a development version of Qt 4.8 compiled with QPA (Lighthouse) support. It installs into /opt/qt-qpa because it's binary incompatible with non-QPA versions of Qt (like the stock one).

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No protocol specified

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Unable to init server: Could not connect: Connection refused

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=== Usage ===

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(gedit:2349): Gtk-WARNING **: cannot open display: :0

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At first, you need a working Wayland compositor, like the one from demo applications, or an experimental version of KWin.

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}}

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Then compile any qmake-based Qt project:

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Before Wayland, running GUI applications with elevated privileges could be properly implemented by creating a [[Polkit]] policy, or more dangerously done by running the command in a terminal by prepending the command with {{ic|sudo}}; but under (X)Wayland this does not work anymore as the default has been made to only allow the user who started the X server to connect clients to it (see the [https://bugzilla.redhat.com/show_bug.cgi?id=1266771 bug report] and [https://cgit.freedesktop.org/xorg/xserver/commit/?id=c4534a3 the] [https://cgit.freedesktop.org/xorg/xserver/commit/?id=4b4b908 upstream] [https://cgit.freedesktop.org/xorg/xserver/commit/?id=76636ac commits] it refers to).

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$ export PATH=/opt/qt-qpa/bin:$PATH

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$ export LD_LIBRARY_PATH=/opt/qt-qpa/lib

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$ qmake

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$ make

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And run it by executing the compiled binary:

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The most straightforward workaround is to use [[xhost]] to temporarily allow the root user to access the local user's X session. To do so, execute the following command as the current (unprivileged) user[https://bugzilla.redhat.com/show_bug.cgi?id=1274451#c64]:

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$ export LD_LIBRARY_PATH=/opt/qt-qpa/lib

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xhost si:localuser:root

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$ export QT_QPA_PLATFORM=waylandgl

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$ ./binaryname

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=== Qt Compositor ===

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To remove this access after the application has been closed:

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There is ongoing work to make [http://labs.qt.nokia.com/2011/03/18/multi-process-lighthouse/ Qt-Compositor], a base layer to make custom Qt compositors on top of Wayland.

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xhost -si:localuser:root

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== Other GUI libraries ==

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{{Note|1=This [https://bugzilla.gnome.org//show_bug.cgi?id=772875 GNOME bug report] suggests two other workarounds, with one specific to editing text files.}}

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([http://wayland.freedesktop.org/toolkits.html page from official website])

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===GTK+===

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{{Style|Many of these subsections should go into a "Known issues" section (i.e., there is no solution currently). Additionally prepending a date is not needed.}}

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With GTK+ 3.0, GTK+ gained support for multiple backends at runtime and can switch between backends in the same way Qt can with lighthouse. The Wayland support is on the upstream GTK+ master branch but disabled by default. To try GTK+ on Wayland, check out gtk+ and pass <code>--enable-wayland</code> to configure:

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=== LLVM assertion failure ===

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If you get an LLVM assertion failure, you need to rebuild {{Pkg|mesa}} without Gallium LLVM until this problem is fixed.

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$ git clone git://git.gnome.org/gtk+

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This may imply disabling some drivers which require LLVM.

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$ cd gtk+

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You may also try exporting the following, if having problems with hardware drivers:

When both Wayland and X backends are enabled, GTK+ will default to the X11 backend, but this can be overridden by setting the <code>GDK_BACKEND</code> environment variable to <code>wayland</code>.

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$ export EGL_DRIVER=/usr/lib/egl/egl_gallium.so

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{{Note|Alternatively, you can install {{AUR|gtk3-git}} from the [[AUR]].}}

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=== Slow motion, graphical glitches, and crashes ===

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Gnome-shell users may experience display issues when they switch to Wayland from X. One of the root cause might be the {{ic|1=CLUTTER_PAINT=disable-clipped-redraws:disable-culling}} set by yourself for Xorg-based gnome-shell. Just try to remove it from {{ic|/etc/environment}} or other rc files to see if everything goes back to normal.

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===Clutter===

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=== nemo ===

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(20161229) prevent that the desktop is created <ref>[https://github.com/linuxmint/nemo/issues/1343 nemo issue 1343]</ref>

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gsettings set org.nemo.desktop show-desktop-icons false

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The Clutter toolkit has a Wayland backend that allows it to run as a Wayland client. The backend is in the master branch of the [http://git.gnome.org/browse/clutter main repo] and can be activated by passing <code>--with-flavour=wayland</code> to the configure script.

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=== X11 on tty1, wayland on tty2 ===

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(20161209) windows of gnome applications end up on tty2 no matter where started ([https://bugzilla.gnome.org/show_bug.cgi?id=774775 gnome issue 774775)]

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===SDL===

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=== gnome wayland on tty1, weston on tty2 ===

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(20170106) apps started on gnome with WAYLAND_DISPLAY set to westen make it not respond any more ([https://bugs.freedesktop.org/show_bug.cgi?id=99489 wayland issue 99489])

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Benjamin Franzke is working on a port of SDL to Wayland, it's available in his [http://cgit.freedesktop.org/~bnf/sdl-wayland/ sdl-wayland repo] on freedesktop.org. Further development upon Benjamins work was done by Andre Heider in his [https://github.com/dhewg/libsdl/tree/wl wayland branch] of libsdl.

Currently only {{AUR|green-recorder}} supports screen recording on Wayland (requires a GNOME session).

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==Window managers and desktop shells==

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=== remote display ===

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(20161229) there was a merge of FreeRDP into weston in 2013, enabled via compile time switch. The arch linux weston package currently has it not enabled.

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===KDE===

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=== Input grabbing in games, remote desktop and VM windows ===

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The KDE Wayland support is expected to come in three phases, with the first two phases expected to be completed this year during the KDE SC 4.8 and 4.9 development cycles. Please see [http://community.kde.org/KWin/Wayland here] for details.

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In contrast to Xorg, Wayland does not allow exclusive input device grabbing, also known as active or explicit grab (e.g. [https://tronche.com/gui/x/xlib/input/XGrabKeyboard.html keyboard], [https://tronche.com/gui/x/xlib/input/XGrabPointer.html mouse]), instead, it depends on the Wayland compositor to pass keyboard shortcuts and confine the pointer device to the application window.

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Also, there is [http://blog.martin-graesslin.com/blog/2011/03/kwin-at-gsoc-2011/ early work] to make it possible to run KWin (KDE's window manager) on Wayland.

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This change in input grabbing breaks current applications' behavior, meaning:

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* Hotkey combinations and modifiers will be caught by the compositor and won't be sent to remote desktop and virtual machine windows.

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* The mouse pointer will not be restricted to the application's window which might cause a parallax effect where the location of the mouse pointer inside the window of the virtual machine or remote desktop is displaced from the host's mouse pointer.

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===GNOME===

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Wayland solves this by adding protocol extensions for Wayland and XWayland. Support for these extensions is needed to be added to Wayland compositors, and in the case of native Wayland clients to widget toolkits (e.g GTK, QT) and probably also to the applications themselves.

Latest revision as of 18:39, 14 March 2018

Wayland is a protocol for a compositor to talk to its clients, as well as a library implementing this protocol. Many major Linux desktop environments, like Gnome and KDE, support Wayland. There is also a compositor reference implementation called "Weston". XWayland implements a compatibility layer to seamlessly run legacy X11 applications on Wayland.

Screencast recording

Weston has build-in screencast recording which can be started and stopped by pressing the Super+r key combination. Screencasts are saved to the file capture.wcap in the current working directory of Weston.

The WCAP format is a lossless video format specific to Weston, which only records the difference in frames. To be able to play the recorded screencast, the WCAP file will need to be converted to a format which a media player can understand. First, convert the capture to the YUV pixel format:

Velox is a simple window manager based on swc. It is inspired by dwm and xmonad.

Orbital

Stacking

Orbital is a Wayland compositor and shell, using Qt5 and Weston. The goal of the project is to build a simple yet flexible and good looking Wayland desktop. It is not a full fledged DE but rather the analogue of a WM in the X11 world, such as Awesome or Fluxbox.

Liri Shell

Stacking

Liri Shell is the desktop shell for Liri, built using QtQuick and QtCompositor as a compositor for Wayland.

Maynard

(Unclear)

Maynard is a desktop shell client for Weston based on GTK. It was based on weston-gtk-shell, a project by Tiago Vignatti.

Motorcar

(Unclear)

Motorcar is a Wayland compositor to explore 3D windowing using virtual reality.

Way Cooler

Tiling

way-coolerAUR is a customizable (Lua config files) Wayland compositor written in Rust. Inspired by i3 and awesome.

Grefsen is a Qt/Wayland compositor providing a minimal desktop environment.

Some of installed wayland desktop clients might store information in /usr/share/wayland-sessions/*.desktop files about how to start them in wayland.

Troubleshooting

Running graphical applications as root

Trying to run a graphical application as root via su, sudo or pkexec in a Wayland session (e.g.GParted or Gedit), be it in a terminal emulator or from a graphical component, will fail with an error similar to this:

Before Wayland, running GUI applications with elevated privileges could be properly implemented by creating a Polkit policy, or more dangerously done by running the command in a terminal by prepending the command with sudo; but under (X)Wayland this does not work anymore as the default has been made to only allow the user who started the X server to connect clients to it (see the bug report and theupstreamcommits it refers to).

The most straightforward workaround is to use xhost to temporarily allow the root user to access the local user's X session. To do so, execute the following command as the current (unprivileged) user[1]:

xhost si:localuser:root

To remove this access after the application has been closed:

xhost -si:localuser:root

Note: This GNOME bug report suggests two other workarounds, with one specific to editing text files.

Reason: Many of these subsections should go into a "Known issues" section (i.e., there is no solution currently). Additionally prepending a date is not needed. (Discuss in Talk:Wayland#)

LLVM assertion failure

If you get an LLVM assertion failure, you need to rebuild mesa without Gallium LLVM until this problem is fixed.

This may imply disabling some drivers which require LLVM.
You may also try exporting the following, if having problems with hardware drivers:

$ export EGL_DRIVER=/usr/lib/egl/egl_gallium.so

Slow motion, graphical glitches, and crashes

Gnome-shell users may experience display issues when they switch to Wayland from X. One of the root cause might be the CLUTTER_PAINT=disable-clipped-redraws:disable-culling set by yourself for Xorg-based gnome-shell. Just try to remove it from /etc/environment or other rc files to see if everything goes back to normal.

weston-terminal

liteide

screen recording

Currently only green-recorderAUR supports screen recording on Wayland (requires a GNOME session).

remote display

(20161229) there was a merge of FreeRDP into weston in 2013, enabled via compile time switch. The arch linux weston package currently has it not enabled.

Input grabbing in games, remote desktop and VM windows

In contrast to Xorg, Wayland does not allow exclusive input device grabbing, also known as active or explicit grab (e.g. keyboard, mouse), instead, it depends on the Wayland compositor to pass keyboard shortcuts and confine the pointer device to the application window.

This change in input grabbing breaks current applications' behavior, meaning:

Hotkey combinations and modifiers will be caught by the compositor and won't be sent to remote desktop and virtual machine windows.

The mouse pointer will not be restricted to the application's window which might cause a parallax effect where the location of the mouse pointer inside the window of the virtual machine or remote desktop is displaced from the host's mouse pointer.

Wayland solves this by adding protocol extensions for Wayland and XWayland. Support for these extensions is needed to be added to Wayland compositors, and in the case of native Wayland clients to widget toolkits (e.g GTK, QT) and probably also to the applications themselves.